Phase transitions and pairing signature in strongly attractive Fermi atomic gases

Journal Article · Wed Aug 15 04:00:00 EDT 2007 · Physical Review. B, Condensed Matter and Materials Physics

DOI:https://doi.org/10.1103/PHYSREVB.76.085120· OSTI ID:21055137

Guan, X W; Bortz, M ^[1]; Batchelor, M T ^[1]; Lee, C ^[2]

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1. Department of Theoretical Physics, Research School of Physical Sciences and Engineering, Australian National University, Canberra, Australian Capital Territory 0200 (Australia)
2. Nonlinear Physics Centre and ARC Centre of Excellence for Quantum-Atom Optics, Research School of Physical Sciences and Engineering, Australian National University, Canberra, Australian Capital Territory 0200 (Australia)

We investigate pairing and quantum phase transitions in the one-dimensional two-component Fermi atomic gas in an external field. The phase diagram, critical fields, magnetization, and local pairing correlation are obtained analytically via the exact thermodynamic Bethe ansatz solution. At zero temperature, bound pairs of fermions with opposite spin states form a singlet ground state when the external field H<H{sub c1}. A completely ferromagnetic phase without pairing occurs when the external field H>H{sub c2}. In the region H{sub c1}<H<H{sub c2}, we observe a mixed phase of matter in which paired and unpaired atoms coexist. The phase diagram is reminiscent of that of type II superconductors. For temperatures below the degenerate temperature and in the absence of an external field, the bound pairs of fermions form hard-core bosons obeying generalized exclusion statistics.

• OSTI ID: 21055137
• Journal Information: Physical Review. B, Condensed Matter and Materials Physics, Journal Name: Physical Review. B, Condensed Matter and Materials Physics Journal Issue: 8 Vol. 76; ISSN 1098-0121
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
BOSONS
CRITICAL FIELD
FERMIONS
FERROMAGNETISM
GASES
GROUND STATES
MAGNETIZATION
ONE-DIMENSIONAL CALCULATIONS
PHASE DIAGRAMS
PHASE TRANSFORMATIONS
SPIN
TYPE-II SUPERCONDUCTORS